Homo sapiens U23 snoRNA.
This H/ACA box RNA was cloned by L.-H. Qu, P. Ganot and J.-P. Bachellerie (unpubl.). Its role in guiding pseudouridylation of U93 of 18S rRNA was evidenced by Ganot et al. (1997a). The pseudouridylation of this residue was experimentally confirmed by primer extension mapping (Kiss et al., 2004). U23 and the C/D box snoRNAs U20 and U82 share the same host gene (nucleolin).
Vertebrate sequences presented reside in the nucleolin gene (intron 12). In the zebrafish, a close copy, U23-2, resides in intron 10.